JPH0798371A - Position confirming system - Google Patents

Abstract

PURPOSE:To simplify receivers and improve the reception performance by receiving the signals of transmitters transmitting inherent signals respectively at a plurality of receiving stations arranged according to a zone constitution. CONSTITUTION:The subject region is divided into three zones A, B, C. Receivers 2a-2c are installed on the ceiling near the centers of the zones A, B, C. The receivers 2a-2c are connected to a backbone communication network 1, and the signals received by the receivers 2a-2c are collected to a central office via the communication network 1. Filtering and amplification are performed at the receiving stations 2a-2c, and the powers or amplitudes of the signals from transmitters (a)-(c) are measured respectively. The measured values are sent to the central office through the communication network 1. The transmitters (a)-(c) generating specific signals are given to workers respectively, the receivers 2a-2c in individual zones A, B, C have functions to identify all signals respectively, thus in which zones the workers are located can be estimated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position confirmation system, and more particularly to a system for performing position confirmation as accurately as possible with a small number of receiving stations, and presuming that the powers or amplitudes of signals received by the respective receiving stations are mutually compared. (EN) A position confirmation system having a means-based system, a transmitter means of a transmitter and a receiver means of a receiver, which constitute the system. For example, it is applied to indoor wireless communication, mobile communication, and personal communication.

[0002]

2. Description of the Related Art As a publicly known document describing the prior art according to the present invention, for example, "Optical Message Communication System (CA)
Outline of NS) and future business development ”(Koji Nagata, Business Communication, '91 Vol.28 No.1, pp.128)
There is ~ 135). This document relates to a system using infrared rays, which is a system including an ID pen and a message card carried by each worker, an optical transceiver and an optical sensor mounted on the ceiling, and bidirectional communication is performed using the optical transceiver. At the same time, we are confirming whereabouts using an optical sensor.

As a position confirmation system, several systems using radio waves or infrared rays have been proposed. These systems have receivers installed at appropriate intervals on an indoor ceiling to receive an identification signal transmitted from a target worker. By doing so, the position of the target is confirmed. These conventional systems use a method of deciding that a worker exists in the vicinity of a receiver by arranging the receiver so that the signal from the target worker is received by only one of the receivers. There is. However, with this method, the reception directivity of each receiver must be sharpened in order to accurately confirm the position, but it is necessary to install a large number of receivers accordingly. For example, the optical sensor used for position confirmation in the system example of the reference document using infrared communication performs transmission / reception within a radius of 1 to 2 m.

FIG. 23 is a diagram showing a conceptual diagram of a conventional position confirmation system. Infrared sensors and antennas are installed at several places on the ceiling of the corridor, at the entrance and ceiling of the room, and when a target object, such as an office worker, is targeted, the signal is received from the transmitter carried by the worker and the identification data is read. Have confirmed. The purpose of such a conventional system is to confirm the presence or absence of an object in the place where the sensor or antenna is installed, so that the signals from the workers should not reach the two receivers at the same time between the receiving stations. This system is unsuitable for confirming the position in a wide range such as in an office with a large room, because it is necessary to be sufficiently far away from each other and especially when using radio waves, only extremely rough position estimation can be performed. When infrared rays are used, there is a drawback in that many receivers must be installed vertically and horizontally in the target area, which is inefficient.

[0005]

[Object] The present invention has been made in view of the above circumstances, and estimates that the power or amplitude of signals received by each receiving station are mutually compared as a system for performing position confirmation as accurately as possible with a small number of receiving stations. To provide a position confirmation system having a means-based system, a transmitter means of a transmitter and a receiver means of the system, and to simplify a receiver or improve reception performance. It was made for the purpose of providing a position confirmation system.

[0006]

In order to achieve the above object, the present invention provides (1)
A transmitter that emits a unique signal is carried by a movable object existing in a limited range, and each signal is monitored and received by a plurality of receiving stations arranged according to an arbitrary zone configuration, and the amount of received signal power is increased. Estimating means for estimating in which zone the transmitter possessed by each target exists by comparing the reception level at each receiving station, and further,
(2) Carriers of different frequencies are assigned as signals to be transmitted by the respective targets and are continuously transmitted, and the receiving stations in each zone prepare filters as many as the allocated frequencies to separate the signals from the respective targets. Having a means for estimating the zone in which the target exists by comparing the power or amplitude of the received signals between the receiving stations for each signal, and further, (3) Using a carrier wave, the transmitter of each target continuously transmits a signal that has been spread and modulated with a pseudo noise code unique to each target, and the receiving station in each zone uses the same pseudo noise code as the pseudo noise code assigned to each target. Correlation calculation using the noise signal as a reference signal,
Having a zone estimation means for determining in which zone the target exists by comparing the magnitudes of the pseudo noise signals between the receiving stations, and (4) above (2) Or (3) having a transmitting means in a position confirmation system for intermittently operating the transmitters of the respective objects using the estimating means at intervals according to the time required for the measuring object to move in the zone; (5) The above (2) or (3) using the transmitting means described in (4) above.
A receiving station of the position confirmation system according to the estimation means described, wherein the power consumption or amplitude of a signal intermittently received from each of the objects is measured only during the time when the transmission is made to determine the in-zone. (6) Unique identification data is assigned to each of the objects, and a carrier of the same frequency, which is data-modulated by an arbitrary modulation method by the identification data, is used as a signal transmitted by each object. The target emits an identification signal intermittently at unique and different time intervals for each target, and the receiving station in each zone demodulates the modulated signal and extracts the identification data to identify the received signal. Having a zone estimation means for deciding in which zone the target exists by comparing the power or amplitude of each of the signals between the receiving stations, and (7) A position confirmation system using the intermittent transmission means described in (5) and the pseudo noise signal described in (3), wherein the transmission intervals of the signals from the respective objects are set to unique and different time intervals for each object. (8) A position confirmation system using the receiving means described in (5) above, wherein the start point of transmission from the transmitter of each target is within a certain fixed time. (9) A position confirmation system using the receiving means described in (5) above, which has a means for transmitting an identification signal that is controlled so as to change over time. Having a transmission means of an identification signal for controlling the transmission time so as to change with time within a certain fixed time, or (10) unique to each movable object existing in a limited range Na Sending a transmitter that issues a signal, monitoring each signal at multiple receiving stations arranged according to an arbitrary zone configuration, and comparing the magnitude of received signal power at each receiving station In a position confirmation system that estimates which zone the machine is in, assigns carrier waves of different frequencies as signals to be transmitted by each target and makes them transmit continuously, and the receiving stations in each zone send each received signal to a constant intermediate frequency. A local oscillator that generates a number of reference signals according to the assigned frequency for frequency conversion is prepared, and the signals from each target are separated by switching the frequency at any timing, and the power or amplitude of these received signals is Having a zone estimation means for determining in which zone the target exists by comparing between the receiving stations for each signal, further, (1
1) In the above (10), a carrier having the same frequency is used to continuously transmit a signal spread-modulated with a pseudo noise code unique to each target from a transmitter of each target, and each zone receiving station targets each target. Has one reference signal generator for generating all the pseudo-noise codes assigned to the reference signal generator, switches reference signals from the reference signal generator at arbitrary time intervals, sequentially performs correlation calculation, and determines their magnitudes. It is characterized by having a zone estimation means for deciding in which zone the target exists by comparing between the receiving stations for each pseudo-noise signal. Hereinafter, description will be given based on examples of the present invention.

FIG. 1 is a diagram showing a zone configuration example of a position confirmation system according to the present invention. In the figure, 1 is a backbone communication network, 2a to 2c are receiving stations, and 3a to 3c are zones.
The target area is divided into a plurality of zones 3a to 3c having a radius according to the specifications. In the example of FIG. 1, the target area is divided into three zones (A, B, C). Receivers 2a to 2c are installed on the ceiling around the center of each zone,
These receivers 2a to 2c are connected to the backbone communication network 1, and the signals received by each receiver are collected by the central office via this communication network. This communication network may be a dedicated line for this system or a LAN such as Ethernet. A unique signal is emitted from each transmitter and received by the receiver in each zone. The signal may be transmitted with a radiation characteristic close to omnidirectional in the ceiling direction. Further, the carrier of the radiated signal may be a radio wave, a light wave, or a sound wave as long as the above-mentioned radiation characteristic is observed.

FIG. 2 is a block diagram of a receiving station of the position confirmation system according to the present invention. In the figure, 4 is a receiving antenna, 5 is a front end section, 6 is a signal identifying section, and 7a and 7b are power / amplitude measuring sections. , 8 is a central station, 9 is a comparison unit, and other parts having the same functions as those in FIG.

In the following description, all of the embodiments will be described using radio waves. In the receiving stations 2a to 2c, after being filtered and amplified by the front end unit 5, after passing through a signal identifying unit 6 according to a transmission signal from the transmitter, the power or amplitude of the signal from each transmitter is measured. It This measurement value is sent to the central office through the backbone communication network 1. Since the radio wave is attenuated as the propagation distance is longer, by comparing the signal powers from the certain transmitters a to c measured by the respective receivers a, b, and c, it is possible to determine which zone the worker having the transmitter belongs to. You can know if you are near the transmitter. By providing each worker with a transmitter that generates a specific signal, and having the receivers in each zone have the function of identifying all of those signals, it is possible to estimate in which zone each worker is located and confirm the position. It will be possible.

Next, the invention according to claim 2 will be described. The invention according to claim 2 relates to the system according to claim 1, in which the signal from the transmitter carried by each worker can be identified at the frequency of the carrier to estimate the zone in which the worker is located. .

FIG. 3 is a diagram showing a configuration example of a transmitter. In the figure, 10a and 10b are oscillators, 11a and 11b are amplifiers, and 12a and 12b are transmitting antennas. The transmitter is an oscillator 10 that generates a signal of a specific frequency for each worker.
a, 10b and amplifiers 11a, 11b. Figure 3
In the above example, the transmitter of the worker 1 transmits the carrier of frequency f1 and the transmitter of the worker 2 transmits the carrier of frequency f2. These signals may or may not be modulated as long as they have constant amplitude. Further, the band of the signal has only to be narrow enough to allow the carrier signals from the workers 1 and 2 to be separated by the band filter of the zone receiver.

FIG. 4 is a diagram showing an example of the configuration of a receiver. In the figure, 13 is a receiving antenna, 14 is a BPF (Band Pass Filtration).
lter: bandpass filter), 15 is an amplifier, 16 is a frequency conversion unit, 17 is a multiplier, 18 is a local oscillator, 19 is an amplifier, 20 is a BPF, 21 is a square-law detector, and 22 is an integrator.

The band-pass filter in the front-end section has a band sufficient to pass all signals (frequency: f1 to fn) to be measured. The received signal is identified by the narrow band pass filter 20 corresponding to each frequency only after frequency conversion. Each signal is squared detector 2
1 and the integrator 22 to measure as a power value. Although the power is measured in this embodiment, the amplitude value may be measured by envelope detection. The power value of each of the signals of frequencies f1 to fn is measured, the value is subjected to appropriate signal processing necessary for communication, and then sent to the central office via the communication network. At the central office, as shown in claim 1,
By investigating the magnitude of the measured value from the receiver in each zone, the zone in which each worker is located can be continuously estimated in real time. In the system of the present invention, since the transmitted signal does not need to be modulated, the structure of the transmitter is simplified, and at the same time the signal can be discriminated by the narrow band filter in the receiver. Occurs.

Next, the invention according to claim 3 will be described. According to the invention of claim 3, in the system of claim 1, the signal from the transmitter carried by each worker can be identified by the pseudo noise code assigned to each worker to estimate the zone in which the worker is located. It is about the system to do.

FIG. 5 is a diagram showing another configuration example of the transmitter,
In the figure, 30a and 30b are PN signal (PN) generators, 31
a, 31b are amplifiers, 32a, 32b are transmitting antennas,
33a and 33b are multipliers, and 34a and 34b are local oscillators. The transmitter includes pseudo noise generators 30a and 30b that generate a specific pseudo noise signal for each worker, oscillators 34a and 34b that generate a signal of a carrier frequency, and an amplifier 31.
It is composed of a and 31b. In the example of FIG. 5, the transmitter of the worker 1 transmits the carrier modulated by the pseudo noise signal PN1, and the transmitter of the worker 2 transmits the carrier modulated by the pseudo noise signal PN2. These carriers share the same frequency band centered on the frequency f0. For the pseudo noise signal, for example, an M sequence code may be used. Further, the band of the pseudo noise signal is not particularly limited, and therefore the pulse length of the pseudo noise signal may be arbitrarily determined.

FIG. 6 is a diagram showing another configuration example of the receiver.
In the figure, 35 is a receiving antenna, 36 is a BPF, 37 is an amplifier, 38 is a frequency converter, 39 is a local oscillator, 40 is a multiplier, 41 is an amplifier, and 42 is a matched filter (PN1 to P).
Nn), 43 is an envelope detector, 44 is a peak hold circuit, 45 is a clock oscillator, 46 is a counter, and 47 is A.
It is a / D converter.

The band-pass filter in the front end section has a band that allows the pseudo noise signal to pass through sufficiently. The received signal is frequency-converted and then input to the matched filter 42 corresponding to the pattern of each pseudo noise code. The amplitude of the output signal of the matched filter 42 becomes maximum when PN1 is input in the case of a matched filter of PN1, for example. Therefore, the amplitude of the output signal of the matched filter is obtained by envelope detection, the peak value is held for one cycle of the pseudo noise signal, and the amplitude value is measured after one cycle time. It is possible to know the transmission signal power of. In this embodiment, the amplitude is measured by A / D.
The converter 47 carries out the converted digital signal as signal power data of PN1 after appropriate signal processing necessary for communication, and then sends it to the central office via the communication network. As described in claim 1, the central station can estimate the zone in which each worker is located at each cycle time of the PN code by checking the magnitude of the measured value from the receiver in each zone.

Since the signals transmitted in the system of the present invention use the same frequency band, the number of transmitters can be increased simply by replacing the chip (for example, ROM) that determines the sign of the pseudo noise signal generator. There is an advantage that the number of workers can be appropriately increased or decreased. Also in the receiver, the matched filter can be configured by a digital correlator, and the target code can be changed by software, so that there is an advantage that the configuration is simplified.

Next, the invention according to claim 4 will be described. The transmitter used in the systems of claims 2 and 3 is configured to continuously transmit the identification signal. Therefore, the position of the worker can be confirmed continuously in the system of claim 2 and in the system of claim 3 in each period of the pseudo noise signal. However, in reality, workers may not frequently move between zones depending on the environment, and in such a case, position confirmation may be performed intermittently. Claim 4
Is a transmission system that intermittently transmits an identification signal assuming such an environment.

FIG. 7 is a diagram showing another example of the configuration of the transmitter. In the figure, 51 is a clock oscillator, 52 is a counter module, 53 is an oscillator, 54 is an amplifier, and 55 is a transmitting antenna. FIG. 7 is a configuration example of a transmitter used in the system of claim 2. Transmission of the identification signal is controlled by an on / off trigger signal from the counter module 52.
The transmitted signal is as shown in FIG. The counter module 52 counts the number of pulses of the clock signal supplied from the clock generator 51, and measures the times T1 and T2. The counter module 52 is composed of one or more counters and can count two or more types of pulses. If transmission has already been made at the start of power supply to the transmitter, T1 is first measured from that point. The counter module generates an off-trigger signal after measuring the time T1, and the signal is used as a trigger to turn off the oscillator output. This signal also acts as a trigger to reset the counter function of the counter module and at the same time start measuring the time T2. After measuring the time T2, the counter module generates an on-trigger signal and the oscillator output is turned on. This signal also serves as a trigger to reset the counter function of the counter module and at the same time start measuring the time T1.

By repeating this operation, the identification signal as shown in FIG. 8 is intermittently transmitted. The time T1 may be any time that is sufficient for the power or amplitude to be measured by the zone receiver. The setting of the time T2 is also arbitrary in principle, but considering that the position confirmation system has the function of tracking the zone in which the worker is located, the length is such that the worker does not miss the movement between the zones. Must be set to. This will depend on the size of the zones in the system. For example, if the distance between the zone receivers is 1 [m], the moving speed of the worker is set to v [m / s], and T2 is set to a time equal to or less than the condition that the worker does not pass through the adjacent zone when moving, and T2 <
It may be set to 1/2 / v [sec].

FIG. 9 is a diagram showing an example of the structure of a transmitter used in the system of claim 3, wherein 56 is a clock generator.
57 is a counter module, 58 is a PN signal (PN1)
A generator, 59 is a multiplier, 60 is a local oscillator, 61 is an amplifier, and 62 is a transmission antenna.

As in FIG. 7, the transmission of the identification signal is controlled by the on / off trigger signal from the counter module 57. The transmitted signal is as shown in FIG. The counter module 57 counts the number of pulses of the clock signal supplied from the clock generator 58 and measures the times T1 and T2. When the power of the transmitter is turned on, an on-trigger signal is sent from the counter module 57 to turn on the local oscillator 60. This signal is simultaneously sent to the PN signal generator 5
Start 8. The counter module 57 counts the pulses from the clock generator 56 after the power is turned on and measures the identification signal transmission time T1. The counter module 57 generates an off-trigger signal after measuring the time T1, and the oscillator output is turned off by using the signal as a trigger.

In this embodiment, this trigger signal is further P
The N signal generator is also turned off, but this is not required. This signal further acts as a trigger to reset the counter function of the counter module 57 and at the same time start measuring the time T2. After measuring the time T2, the counter module 57 generates an on-trigger signal and the oscillator output is turned on. In this embodiment, the trigger signal is PN
The signal generator 58 is turned on. This signal further acts as a trigger to reset the counter function of the counter module 57 and at the same time start measuring the time T1. This operation is repeated and the identification signal as shown in FIG. 10 is intermittently transmitted.

The setting of the time T1 is different from that of the transmitter of FIG. Since the transmitted identification signal is a PN signal, it needs to be transmitted over a period of one cycle or more. Therefore, T1 is set so that T1> PN signal period.
The setting of the time T2 may be the same as in the case of FIG.
As described above, according to the present invention, since the transmitter can intermittently transmit the identification signal, power consumption of the transmitter carried by the worker can be saved, which leads to an advantage that the capacity of the driving battery can be reduced. .

Next, the invention according to claim 5 will be described. When receiving the identification signal from the transmitter using the intermittent transmission system according to claim 4, it is premised that the identification signal is continuously transmitted in the receiving system according to claims 2 and 3. Moreover, the received power is measured even during the period when the signal is not transmitted. In this case, the power and noise power of the multipath signal are measured, and the zone in which the worker is located becomes undefined during the period when the signal is not transmitted. In order to solve such a problem, the fifth aspect shows a receiving method for measuring only the received signal power during transmission.

11 and 12 are diagrams showing still another example of the configuration of the receiver. In the figure, 71 is a receiving antenna, 72 is a BPF, 73 is an amplifier, 74 is a frequency conversion unit, and 75 is a multiplier. 76 is an amplifier, 77 is a local oscillator, and 78 is a BP
F, 79 is a square wave detector, 80 is an integrator, 81 is a peak hold circuit, 82 is a clock oscillator, 83 is a counter,
84 is an A / D converter, 85 is a receiving antenna, and 86 is BP
F, 87 is an amplifier, 88 is a frequency converter, 89 is a local oscillator, 90 is a multiplier, 91 is an amplifier, 92 is a matched filter, 93 is an envelope detector, 94 is a peak hold circuit,
95 is a clock oscillator, 96 is a counter, 97 is an A / D
It is a converter.

In this configuration example, the measured value is the A / D converter 8
Converted to data at 4,97. The counters 83 and 96 count the pulses from the clock generators 82 and 95 to measure the transmission time interval T1 + T2 of the identification signal.
No data is sent to the central station during this time. Time T1 + T
When the measurement of 2 is completed, data is sent from the A / D converters 84 and 97 by a trigger signal output from the counter and is sent to the central office via the communication network through appropriate processing. At the same time, the trigger signal from the counter prompts the peak hold to be released and the counter to be reset, and the measurement for the next transmission signal starts. As described above, by providing a counter for measuring the sum of the transmission time of the identification signal and the stop time to control the transfer of the measurement data, there is no problem that the existing zone becomes indefinite during the transmission stop time.

Next, the invention according to claim 6 will be described. The visited zone estimation system used in claims 2 to 5 requires a filter or a matched filter for identifying the identification signals of all the workers targeted for the receiver. Claim 6 relates to a system for simplifying the configuration of the receiver. FIG. 13 is a diagram showing still another configuration example of the transmitter, in which 101 is a clock generator, 102 is a counter module, 103 is an oscillator, 104 is a modulator, and 10 is a modulator.
5 is identification data, 106 is an amplifier, and 107 is a transmitting antenna.

The signal from the transmitter is transmitted intermittently as in claim 4, but its carrier frequency is the same,
Further, the identification data is subjected to constant amplitude modulation such as PSK or FSK. The transmitter of each worker operates with a unique transmission time and stop time, and the sum of the transmission time and the stop time is set to be different for each worker transmitter. By setting in this way, the transmission and stop timings are relatively deviated from each other. Therefore, when the number of workers is small, there is a time when only a certain identification signal is issued as shown in FIG. 14 (T ≠ T ').

FIG. 15 is a diagram showing still another configuration of the receiver, in which 108 is a receiving antenna, 109 is a BPF,
110 is an amplifier, 111 is a frequency conversion unit, 112 is a local oscillator, 113 is a multiplier, 114 is an amplifier, and 115 is B.
PF, 116 is a demodulator, 117 is a square wave detector, 118 is an integrator, 119 is a peak hold circuit, and 120 is A / D.
It is a converter.

The received signal is frequency-converted and input to the demodulation section 116 and a circuit for measuring received power. The received signal is modulated with a data packet of a specific format including identification data of the signal and control data regarding power measurement, and these data are demodulated by the demodulation unit 116. The circuit for power measurement is the square-law detector 1 as in the previous example.
17 and an integrator 118. In this configuration example, the peak value is held and adopted as a measurement value,
The A / D converter 120 converts the data. Demodulation unit 1
In addition to the identification data, a trigger signal indicating the end of demodulation of the data packet is sent from 16 and the power measurement data is appropriately processed together with the identification data by this signal and then transmitted to the central office via the communication network. . The central station compares the power measurement data with reference to the identification data, and estimates the zone in which it is located. As described above, according to the present invention, since only one type of filter and power measuring circuit are required for the receiver, it is possible to realize with a simple configuration.

Next, the invention according to claim 7 will be described. In the system using the intermittent transmission system according to the fifth aspect, the same frequency band is used and the signal is identified by the pseudo noise signal. However, one of the problems of the system using the pseudo noise signal is that the cross correlation between the pseudo noises is zero.
Therefore, if the number of workers increases, the output of the matched filter becomes large due to the cross-correlation, and it becomes difficult to identify the target signal.

In the system according to the seventh aspect, the transmitter of each worker operates with a unique transmission time and stop time, and the sum of the transmission time and the stop time is set to be different for each worker transmitter. By setting in this way, the timings of transmission and stop are relatively deviated, so that when there are a small number of workers, there is a time during which only a certain identification signal is issued. The configuration of the transmitter used in this system can be realized in FIG. 9, but it is necessary to set the sum (T1 + T2) of the transmission time and the stop time to be different for each target transmitter.

FIG. 16 is a diagram showing another example of the configuration of the receiver. In the figure, 121 is a receiving antenna, 122 is a BPF,
Reference numeral 123 is an amplifier, 124 is a frequency converter, 125 is a local oscillator, 126 is a multiplier, 127 is an amplifier, and 128-1 ...
128-n is a matched filter, 129a and 129b are envelope detectors, 130a and 130b are peak hold circuits, 1
31a and 131b are counters and 133a and 133b are A
It is a / D converter.

The power measurement for each identification signal is performed after the time peculiar to each signal is measured, but each time is set separately. In the example of FIG. 16, the signal of the worker 1 is measured every (T1 + T2) time and the signal of the worker 2 is measured every (T1 ′ + T2 ′) time.
As described above, since the signals transmitted from the transmitters are temporally shifted, the influence of noise generated by the cross-correlation between the signals is reduced, and more accurate in-zone estimation can be performed.

Next, the invention according to claim 8 will be described. According to claims 6 and 7, it is possible to provide a time in which the signals from the respective objects do not overlap with each other as a time interval that is unique and different for each object. However, although the transmission time and the stop time are relatively different, since each target is fixed, the degree of overlap with signals from other stations is largely due to chance, and it is possible to determine which objects easily overlap and which do not overlap easily. There is also a nature. There is also a problem that the measurement time differs for each object and the frequency with which the position confirmation data is obtained differs for each object.

In the transmitter according to claim 8, the condition that the transmissions from the respective objects are not made at the same time is controlled so that the transmission time is controlled so as to be as fair as possible. Use a transmission method that changes to. FIG. 17A shows an example of a transmission signal according to the present invention. The time T is a constant value which is equal to T1 + T2 in FIGS. 11 and 12 and represents the measurement time. T1 indicates the time when the signal is transmitted. FIG. 17A is an example in which one pattern of the transmission signal is completed in 4T. The signal is transmitted four times at each time T, but the transmission start time is different for each time.

FIG. 18 is a diagram showing still another configuration example of a transmitter when the present invention is applied to the case of transmitting a pseudo noise signal in the system of claim 5, wherein 141 is a clock generator. 142 is a counter module, 143 is a ROM (Re
ad Only Memory), 144 is a PN signal (PN1) generator, 145 is a local oscillator, 146 is a multiplier, 147 is an amplifier, and 148 is a transmission antenna.

For example, in order to obtain the transmission pattern as shown in FIG. 17 (a), the PN signal generator 144 and the local oscillator 145 may be turned on / off using the control signal as shown in FIG. 17 (b). In this embodiment, the ROM 143 shown in FIG.
An on / off signal is output by writing the transmission pattern in (b) and reading it. That is, the clock generator 145 generates a pulse, the counter module 142 counts the pulse and measures the time, and at the same time, converts the pulse into an address signal in parallel. This address signal causes the ROM 143 to output the signal shown in FIG. Assuming that the signal of the transmission pattern is written from the address 00 to the address FF of the ROM 143, the transmission pattern is designed every 4T time by designing the counter module 142 so that the counter is reset by the address signal 100 of the counter module 142. Will be repeated. The present invention has an advantage that the identification signals are transmitted more randomly, and signals from the respective objects are less likely to interfere with each other. Further, since T is constant, the system of claim 5 can be used as it is for receiving a signal from the transmitter of the present invention.

Next, the invention according to claim 9 will be described. In claim 8, the transmission start time is changed with time, but it is also possible to change the transmission time with time during the same measurement time T. In the transmitter according to claim 9, the measuring time T
Is fixed and the transmission time is changed every time, so that a system that tries to receive signals from each object fairly is used. FIG. 19A shows an example of a transmission signal according to the present invention. The time T is a constant value representing the measurement time as in FIGS. 17 (a) and 17 (b). T1 indicates the time when the signal is transmitted. FIG. 17 (a) is an example in which one pattern of the transmission signal is completed in 4T. The signal is transmitted four times at each time T, but the transmission time T1 is different at each time.

FIG. 20 is a diagram showing an example of the configuration of a transmitter when the present invention is applied to the case where a pseudo noise signal is transmitted in the system of claim 5, wherein 151 is a clock generator and 15 is a clock generator.
2 is a counter module, 153 is a ROM, 154 is a local oscillator, 155 is a PN signal (PN1) generator, 156
Is a multiplier, 157 is an amplifier, and 158 is a transmitting antenna.

For example, in order to obtain the transmission pattern as shown in FIG. 19 (a), the PN signal generator 155 and the local oscillator 154 may be turned on / off using the control signal as shown in FIG. 19 (b). In this example, FIG.
An on-off signal is output by writing a sending pattern in the above and reading it. In other words, the clock generator 154 generates a pulse, the counter module 152 counts the pulse, measures the time, and at the same time, converts the pulse into an address signal in parallel. The address signal causes the ROM 153 to output the signal shown in FIG. Assuming that the signal of the transmission pattern is written from the address 00 to the address FF of the ROM 153, the transmission pattern is repeated every 4T time by designing the counter module so that the counter is reset by the address signal 100 of the counter module 152. Will be done. According to the present invention, since the times at which the identification signals are transmitted are different for each measurement time, an effect similar to that of claim 8 is obtained. Further, since T is constant, the system of claim 5 can be used as it is for receiving the signal from the transmitter of the present invention.

The above-described embodiment is a system in which the power or amplitude of signals received by each receiving station are compared with each other as a system for confirming the position as accurately as possible with a small number of receiving stations as compared with a system using infrared rays or the like. A method-based system, a transmitter method of a transmitter and a receiver method of the system are provided. A tenth aspect described below requires a plurality of band-pass filters for continuous reception in contrast to the second aspect, and intermittently performs position confirmation to simplify the configuration of the receiver. .
The eleventh aspect of the present invention requires a plurality of matched filters for continuous reception as compared with the third aspect, and intermittently confirms the position to simplify the configuration of the receiver.

First, the invention according to claim 10 will be described. FIG. 21 is a diagram showing still another configuration example of the receiver,
In the figure, 161 is a receiving antenna, 162 is a BPF, 163.
Is an amplifier, 164 is a multiplier, 165 is an amplifier, 166 is a BPF, 167 is a square wave detector, 168 is an integration dump filter, 169a to 169c are counters, and 170 is RO.
M, 171 is a PLL synthesizer, 172 is a peak hold circuit, 173 is an A / D converter, and 174 is a data processing unit.

The band-pass filter in the front-end section uses the signal to be measured (frequency: F1 + fIF to Fn + fI).
F) Have enough bandwidth to pass everything. All received signals are frequency converted to the intermediate frequency fIF. At this time, the local oscillator used for frequency conversion is P
Like the LL synthesizer 171, it is necessary to have a local oscillator capable of sequentially switching the frequency and supplying a stable frequency signal. In FIG. 21, the PLL synthesizer 1
71 sequentially generates frequencies F1 to Fn, and the frequency-converted signal passes through a square wave detector and an integration dump filter and is measured as power value data. Although the power is measured in this embodiment, the amplitude value may be measured by envelope detection.

The frequency generated by the PLL synthesizer 171 can be switched by, for example, sequentially reading the control data of the synthesizer written in the ROM 170 as shown in FIG. The counter 169b counts the measurement time (square detection and integration time) T of each signal from the reference clock. This output is the peak hold circuit 172, A /
It becomes a trigger signal for the D converter 173, and when this signal is output, the power value of the received signal is stored in the data processing unit 174 as data. This signal is given a delay time to reset the integration dump filter 168. This signal is also input to the counter 169a at the same time.

The counter 169a gives an address signal in which the data of the PLL synthesizer 171 read from the ROM 170 is stored. Here, the ROM 170
It is assumed that n kinds of data from the first address to the nth address are stored and the counter 169a is the counter 1 for measuring the time T.
The output from 69b is counted from 0 to n-1, and the address signal is output to the ROM 170. After n.times.T time, the signal to be measured becomes the signal of the first frequency to be measured again, so the counters 169a and 169b must be linked.

In this embodiment, a counter 169c is provided,
The reference clock used in the counter 169b is used to measure n × T time, and the output signal generated at that time is used as the reset signal of the counter 169a. further,
Since the address information of the ROM 170 is output to the data processing unit 174, the power value being measured is the frequency F1 + fI.
The power value of which signal from F to Fn + fIF is added to the measurement data and sent to the central office via the communication network. The central station can estimate the zone in which each worker is located every n × T time by checking the magnitude of the measured value from the receiver in each zone. According to the method of the present invention, since it is possible to identify a signal with only one narrow band filter in the receiver, there is an advantage that the configuration is simplified.

Next, the invention according to claim 11 will be described. 22 is a diagram showing still another configuration example of the receiver. In the figure, 175a and 175b are local oscillators, 176 is an amplifier, 177 is a convolver, and other parts having the same operations as those in FIG. Is attached. Claim 11
This is a method for estimating the worker's zone by enabling the pseudo noise code assigned to each worker to identify the signal from the transmitter carried by each worker.

The band-pass filter in the front end section has a band that allows the pseudo noise signal to pass through sufficiently. The received signal is frequency-converted and then input to the convolver 177. Since the convolver 177 performs convolutional integration of two signals, one input is a received signal and the other is a reference PN.
By using a signal, the output of the convolver 177 becomes equivalent to the correlation output signal. Therefore, its amplitude is, for example, P
When N1 is used as the reference signal, it becomes maximum when PN1 is received. Therefore, by obtaining the convolver output signal power from the square-law detection and the integrator, holding the peak value for one cycle of the pseudo noise signal, and measuring the amplitude value after one cycle time, PN1 included in the received signal is obtained. The transmission signal power of (from the worker 1) can be known.

Similarly, the PN signals are sent from PN1 to PNn.
The signal from each target can be measured sequentially by changing In this embodiment, the PN signal is sequentially read from the ROM 170. The counter 169b is a counter that measures the period of the PN signal. The reference clock generates a clock having a frequency of the chip rate (chip width Δ), and the counter 169b generates a signal after measuring the cycle m × Δ. This signal serves as a trigger signal for the peak hold circuit and the A / D converter 173, and at the same time, is given a delay time δ, and then resets the integration dump filter 168. Counter 169
a is a counter for measuring the time n × m × Δ, and at the same time is an address signal of the ROM 170 in which n kinds of PN codes from PN1 to PNn are stored.

In this example, m addresses are sequentially provided from 0 address,
The ROM 170 stores n kinds of PN codes up to the address n × m−1. In the counter 169a, time n × m × Δ
Signal is output after the measurement of
To reset. As a result, the address signal to the ROM 170 becomes the address 0 again, and this is repeated. RO
The address signal being accessed is output to the data processing unit 174 so that the target PN signal can be seen from M170. The data processing unit 174 adds this signal to the data of the received signal power value, performs appropriate signal processing necessary for communication as the target signal power data, and then sends it to the central office via the communication network.

At the central station, by checking the magnitude of the measured value from the receiver in each zone, the zone in which each worker is located
This can be estimated for each of “the period time of the PN signal of the code × the number of target workers”. In the method of the present invention, since the correlation output can be measured by one convolver, there are as many matched filters as the number of target workers. There is an advantage that it is not necessary to prepare and the configuration is simple.

[0055]

As is apparent from the above description, the present invention has the following effects. (1) Effect corresponding to claim 1: It is possible to measure the signal power or amplitude from a transmitter carried by a target person or object and compare them between receivers installed in each zone. In order to determine the coverage zone, it is possible to perform more accurate position confirmation with a smaller number of receivers than in a system that uses the receivers as sensors. (2) Effect corresponding to claim 2: Since the transmission signal from the target does not need to be modified, the configuration of the transmitter becomes simple. In addition, the receiver can also identify the signal by a narrow band filter, which simplifies the configuration. (3) Effect corresponding to claim 3: Since the transmission signal from the target is a signal spread-modulated with a pseudo noise signal at the same frequency, a new transmitter can be easily constructed by replacing the pseudo noise signal generator. It is easy to deal with the increase or decrease of the number of objects, and the receiver has the same advantage. (4) Effect corresponding to claim 4: Since the identification signal from the transmitter can be transmitted intermittently, the power consumption of the transmitter can be saved and the transmission can be continued for a longer time. (5) Effect corresponding to claim 5: Since the identification signal from the transmitter can be transmitted intermittently, power consumption of the transmitter can be saved, the transmission can be continued for a longer time, and the transmission stop time can be further reduced. It is possible to avoid the in-zone becoming indefinite in. (6) Effect corresponding to claim 6: Since only one type of band filter, power measuring circuit, or amplitude measuring circuit is required for transmission, the structure of the receiver is simplified. (7) Effect corresponding to claim 7: Since the transmission of signals from the transmitters deviates in time, the influence of noise caused by cross-correlation between the signals is reduced, and more accurate in-zone estimation can be performed. . (8) Effect corresponding to claim 8: Discrimination signals from transmitters are randomly transmitted, signals from respective targets are less likely to interfere with each other, and more accurate in-zone estimation can be performed. (9) Effect corresponding to claim 9: Since the time at which the identification signals from the transmitters overlap is different for each measurement, the time during which the signals from each target do not interfere with each other is likely to occur, resulting in a more accurate presence zone. Can be estimated. (10) Effect corresponding to claim 10: Since the received signal can be identified by one narrow band filter, the configuration of the receiver is simplified. (11) Effect corresponding to claim 11: Since the received signal can be identified by only one convolver, the configuration of the receiver is simplified.

[Brief description of drawings]

FIG. 1 is a diagram showing a zone configuration example of a position confirmation system according to the present invention.

FIG. 2 is a diagram showing a configuration example of a receiving station of the position confirmation system according to the present invention.

FIG. 3 is a diagram showing a configuration example of a transmitter according to the present invention.

FIG. 4 is a diagram showing a configuration example of a receiver according to the present invention.

FIG. 5 is a diagram showing another configuration example of a transmitter according to the present invention.

FIG. 6 is a diagram showing another configuration example of a receiver according to the present invention.

FIG. 7 is a diagram showing still another configuration example of the transmitter according to the present invention.

FIG. 8 is a diagram showing a transmission signal in FIG.

FIG. 9 is a diagram showing still another configuration example of the transmitter according to the present invention.

FIG. 10 is a diagram showing a transmission signal in FIG.

FIG. 11 is a diagram showing still another configuration example of the receiver according to the present invention.

FIG. 12 is a diagram showing still another configuration example of the receiver in the present invention.

FIG. 13 is a diagram showing still another configuration example of the transmitter according to the present invention.

FIG. 14 is a diagram showing an identification signal in FIG.

FIG. 15 is a diagram showing still another configuration example of the receiver according to the present invention.

FIG. 16 is a diagram showing still another configuration example of the receiver in the present invention.

FIG. 17 is a diagram showing a transmission signal in the present invention.

FIG. 18 is a diagram showing still another configuration example of the transmitter according to the present invention.

FIG. 19 is a diagram showing a transmission signal in the present invention.

FIG. 20 is a diagram showing still another configuration example of the transmitter according to the present invention.

FIG. 21 is a diagram showing still another configuration example of the receiver according to the present invention.

FIG. 22 is a diagram showing still another configuration example of the receiver according to the present invention.

FIG. 23 is a conceptual diagram of a conventional position confirmation system.

[Explanation of symbols]

1 ... Backbone communication network, 2a-2c ... Receiving station, 3a-
3c ... Zone, 4 ... Receiving antenna, 5 ... Front end section, 6 ... Signal identifying section, 7a, 7b ... Power / amplitude measuring section,
8 ... Central Office, 9 ... Comparison Department.

Claims (11)

[Claims] 1. A movable object existing in a limited range is caused to carry a transmitter which emits a unique signal,
Estimate in which zone the transmitter of each target is located by monitoring and receiving each signal at multiple receiving stations arranged according to an arbitrary zone configuration and comparing the received signal power levels at each receiving station. And a position confirming system for estimating the position. 2. A carrier of different frequency is allocated as a signal to be transmitted from each target to be transmitted continuously, and a receiving station in each zone prepares filters corresponding to the number of allocated frequencies to separate signals from each target. 2. The apparatus further comprises a zone estimation means for deciding in which zone the target exists by comparing the power or amplitude of the received signals between the receiving stations for each signal. Location confirmation system. 3. A carrier of the same frequency is used to continuously transmit a signal spread-modulated by a pseudo-noise code unique to each target from a transmitter of each target, and assigned to each target at a receiving station in each zone. Correlation calculation is performed using the same pseudo-noise signal as the generated pseudo-noise code as a reference signal, and the magnitudes thereof are compared between the receiving stations for each pseudo-noise signal to determine in which zone the target exists. The position confirmation system according to claim 1, further comprising a zone zone estimation unit. 4. A transmission in a position confirmation system in which the transmitter of each of the objects using the estimation means according to claim 2 or 3 is operated intermittently at intervals according to the time required for the measurement object to move within the zone. The position confirmation system according to claim 1, further comprising means. 5. The receiving station of the position confirmation system by the estimating means according to claim 2 or 3 using the transmitting means according to claim 4, wherein the power or amplitude of a signal intermittently received from each of the objects. 2. The position confirming system according to claim 1, further comprising a receiving unit that determines a zone in which the mobile station is located by measuring only during a time when a call is transmitted. 6. Unique identification data is assigned to each object, and a carrier of the same frequency, which is data-modulated by an arbitrary modulation method by the identification data, is used as a signal transmitted by each object, and each object uses the identification signal for each object. The signals are transmitted intermittently at different time intervals unique to each of the zones, and the receiving stations in each zone demodulate the modulated signals to extract identification data and identify the received signals. 2. The position confirmation system according to claim 1, further comprising estimation means of a zone in which the target is located by comparing between receiving stations for each of them. 7. The intermittent transmitting means according to claim 5 and claim 3.
2. The position confirmation system using the pseudo noise signal described above, further comprising transmitting means for setting a transmission interval of a signal from each of the objects to a time interval unique and different for each object. Position confirmation system. 8. A position confirmation system using the receiving means according to claim 5, wherein the transmission start time point from the transmitter of each of the objects changes temporally within a certain fixed time. 2. The position confirmation system according to claim 1, further comprising transmitting means for transmitting an identification signal to be controlled. 9. A position confirmation system using the receiving means according to claim 5, wherein the transmission time from each of the target transmitters is controlled so as to temporally change within a certain fixed time. 2. The position confirmation system according to claim 1, further comprising an identification signal transmitting means. 10. A mobile object existing in a limited range is provided with a transmitter that emits a unique signal, and a plurality of receiving stations arranged according to an arbitrary zone configuration monitor and receive each signal. , In a position confirmation system that estimates in which zone the transmitter of each target is located by comparing the magnitude of the received signal power at each receiving station, assign carriers of different frequencies as signals transmitted by each target. A local oscillator that generates a number of reference signals according to the assigned frequency is provided at the receiving station in each zone for frequency conversion of each received signal to a constant intermediate frequency, and the frequency is adjusted at any timing. The signals from each target are separated by switching, and the power or amplitude of the received signals is compared between the receiving stations for each signal to determine which zone the target is. A location confirmation system having a means for estimating a zone in which the vehicle is located in the area. 11. A carrier of the same frequency is used to continuously transmit a signal spread-modulated with a pseudo noise code unique to each target from a transmitter of each target, and each zone receiving station is assigned to each target. One reference signal generator for generating all pseudo noise codes, switching reference signals from the reference signal generator at arbitrary time intervals, sequentially performing correlation calculation, and determining the magnitude of each of the pseudo noise signals. 11. The position confirmation system according to claim 10, further comprising estimating means of a zone in which the target is present, by determining in which zone the target exists by comparing between receiving stations for each.